2,028 research outputs found

    Productivity of Florida Springs: final report to Biology Branch, Office of Naval Research progress from December 31, 1955 to May 31, 1956

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    CONTENTS: Factors that control species numbers in Silver Springs, by James L. Yount. Study of the biomass of parasites in the stumpknockers, by Wanda Hunter. Macrophytic communities in Florida inland waters, by Delle N. Swindale. Comment in retrospect, by Howard T. Odum. (15pp.

    Productivity of Florida Springs: Second annual report to Biology Branch, Office of Naval Research progress from January 1 to December 31, 1954

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    Production measurements at different times of the year indicate a linear relationship of light intensity and overall production at about 8% of the visible light energy reaching plant level. Measurements of a coral reef at Eniwetok indicate 6%. Further evidence of breeding at all seasons but with a quantitative pulse in the seasons of maximum light indicates that the seasonal fluctuation in primary production is routed through reproduction rather than through major changes in populations. The succession of plants and anmals of the aufwuchs has been shown with glass slides and counts from Sagittaria blades. Losss of oxygen bubbles during the day and emergence of aquatic insects at night have been measured with funnels. Bell jar measurements are reported for bacterial metabolism on mud surfaces. pH determined CO2 uptake agrees with titration determinations. A few rough estimates of herbivore production have been made from caged snails, aufwuchs succession, and fish tagging. Nitrate uptake a night by aufwuchs communities has been confirmed in a circulating microcosm experiment as well as in bell jars in the springs. Distributions of oxygen and organisms have been used to criticize the saprobe stream classification system. Theoretical consideration of maximum photosynthetic rates in teh literature data indicates logarithmic rate variation inversely with organismal size just as for respiratory metabolism. Extreme pyramid shapes are thus shown for communities in which organismal size decreases up the food chain and for other communities with the same energy influx but with organismal size increasing up the food chain. Literature data is used to further demonstrate the validity of the optimum efficiency-maximum power principle for photosynthesis. Work on plants by Dr. Delle Natelson indicates essential stability of aquatic plant communities after 3 years and about 10-20% reproducibility in previous biomass estimates by Davis. Work on an animal picture of the fishery characteristics by Caldwell, Barry, and Odum is half completed. The study of aquatic insects in relationship to spring gradients by W.C. Sloan has been completed an an M.S. thesis. J. Yount has begun a study of affect of total productivity on community composition using aufwuchs organisms on glass slides placed in different current and light conditions in Silver Springs. (49pp.

    Partisan Politics, Agricultural Interests and Effects on State-Level Ethanol Subsidies

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    This paper examines factors leading to state-level fuel ethanol subsidies. The federal Renewable Fuels Standard (RFS2) mandates a certain volume of ethanol production through 2022. However, the $6 Billion federal ethanol subsidy expired at the end of 2011. Because the mandated amount of ethanol production from corn continues to increase until 2015, there is evidence that ethanol producers may look to the individual states to ensure that higher levels of ethanol production remain profitable. This paper examines factors that have led to state-level policies favoring ethanol in order to predict which states will be more likely to increase subsidies in the absence of the federal program. Using a multiple regression model with data from 1996 through 2010, this project finds that states with larger agricultural sectors and with higher degrees of party competition are more likely to subsidize ethanol while party control has no significant effect

    Delay Discounting as an Index of Sustainable Behavior: Devaluation of Future Air Quality and Implications for Public Health

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    Poor air quality and resulting annual deaths represent significant public health concerns. Recently, rapid delay discounting (the devaluation of future outcomes) of air quality has been considered a potential barrier for engaging in long term, sustainable behaviors that might help to reduce emissions (e.g., reducing private car use, societal support for clean air initiatives). Delay discounting has been shown to be predictive of real world behavior outside of laboratory settings, and therefore may offer an important framework beyond traditional variables thought to measure sustainable behavior such as importance of an environmental issue, or environmental attitudes/values, although more research is needed in this area. We examined relations between discounting of air quality, respiratory health, and monetary gains and losses. We also examined, relations between discounting and self-reported importance of air quality and respiratory health, and nature relatedness. Results showed rapid delay discounting of all outcomes across the time frames assessed, and significant positive correlations between delay discounting of air quality, respiratory health, and monetary outcomes. Steeper discounting of monetary outcomes relative to air quality and respiratory health outcomes was observed in the context of gains; however, no differences in discounting were observed across losses of monetary, air quality, and respiratory health. Replicating the sign effect, monetary outcomes were discounted more steeply than monetary losses. Importance of air quality, respiratory health and nature relatedness were significantly and positively correlated with one another, but not with degree of delay discounting of any outcome, demonstrating the need for more comprehensive measures that predict pro-environmental behaviors that might benefit individuals and public health over time. These results add to our understanding of decision-making, and demonstrate alarming rates of delay discounting of air quality and health. These results implicate a major public health concern and potential barriers to individual and societal behavior that reduce pollution and emissions for conservation of clean air

    Delayed Matching to Sample: Reinforcement has Opposite Effects on Resistance to Change in Two Related Procedures

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    The effects of reinforcement on delayed matching to sample (DMTS) have been studied in two within-subjects procedures. In one, reinforcer magnitudes or probabilities vary from trial to trial and are signaled within trials (designated signaled DMTS trials). In the other, reinforcer probabilities are consistent for a series of trials produced by responding on variable-interval (VI) schedules within multiple-schedule components (designated multiple VI DMTS). In both procedures, forgetting functions in rich trials or components are higher than and roughly parallel to those in lean trials or components. However, during disruption, accuracy has been found to decrease more in rich than in lean signaled DMTS trials and, conversely, to decrease more in lean than in rich multiple VI DMTS components. In the present study, we compared these procedures in two groups of pigeons. In baseline, forgetting functions in rich trials or components were higher than and roughly parallel to those in lean trials or components, and were similar between the procedures. During disruption by prefeeding or extinction, accuracy decreased more in rich signaled DMTS trials, whereas accuracy decreased more in lean multiple VI DMTS components. These results replicate earlier studies and are predicted by a model of DMTS from Nevin, Davison, Odum, and Shahan (2007)

    A first--order irreversible thermodynamic approach to a simple energy converter

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    Several authors have shown that dissipative thermal cycle models based on Finite-Time Thermodynamics exhibit loop-shaped curves of power output versus efficiency, such as it occurs with actual dissipative thermal engines. Within the context of First-Order Irreversible Thermodynamics (FOIT), in this work we show that for an energy converter consisting of two coupled fluxes it is also possible to find loop-shaped curves of both power output and the so-called ecological function against efficiency. In a previous work Stucki [J.W. Stucki, Eur. J. Biochem. vol. 109, 269 (1980)] used a FOIT-approach to describe the modes of thermodynamic performance of oxidative phosphorylation involved in ATP-synthesis within mithochondrias. In that work the author did not use the mentioned loop-shaped curves and he proposed that oxidative phosphorylation operates in a steady state simultaneously at minimum entropy production and maximum efficiency, by means of a conductance matching condition between extreme states of zero and infinite conductances respectively. In the present work we show that all Stucki's results about the oxidative phosphorylation energetics can be obtained without the so-called conductance matching condition. On the other hand, we also show that the minimum entropy production state implies both null power output and efficiency and therefore this state is not fulfilled by the oxidative phosphorylation performance. Our results suggest that actual efficiency values of oxidative phosphorylation performance are better described by a mode of operation consisting in the simultaneous maximization of the so-called ecological function and the efficiency.Comment: 20 pages, 7 figures, submitted to Phys. Rev.

    Human seminal plasma contains somatostatin-64

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    Finding Comfort and Discomfort Through Foodways Practices During the COVID-19 Pandemic: A Public Folklore Project

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    This article describes an international oral history project run by the nonprofit Center for Food and Culture on how individuals found both comfort and discomfort through foodways during the COVID-19 pandemic. The project expanded the concept of comfort food to include the range of activities included within foodways and also explored the variety of meanings attached to the concept, emphasizing that both “food” and “comfort” are culturally and socially constructed. The project resulted in an archive of documentation from over 65 interviews, a virtual symposium, and an on-line exhibit. The exhibit and resources on comfort food, folkloristic approaches to foodways, and oral history methods are posted on a free website (www.foodandculture.org). As such, the project is an example of public folklore presentations of folkloristic concepts and materials. It also illustrates public humanities in its exploration of the meanings of comfort foodways during the pandemic. This paper describes the findings from this project and discusses their implications for insights into individuals’ experiences around foodways practices during the pandemic. The lead author designed and directed the project; the additional authors contributed in its development, conducted interviews, participated in the symposium and exhibit, and offered commentary and insights on this paper

    Continuous Nicotine Exposure Does Not Affect Resurgence of Alcohol Seeking in Rats

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    Alcohol is the most commonly used drug in the United States and alcohol abuse can lead to alcohol use disorder. Alcohol use disorder is a persistent condition and relapse rates following successful remission are high. Many factors have been associated with relapse for alcohol use disorder, but identification of these factors has not been well translated into preventative utility. One potentially important factor, concurrent nicotine use, has not been well investigated as a causal factor in relapse for alcohol use disorder. Nicotine increases the value of other stimuli in the environment and may increase the value of alcohol. If nicotine increases the value of alcohol, then nicotine use during and after treatment may make relapse more probable. In the current study, we investigated the effect of continuous nicotine exposure (using osmotic minipumps to deliver nicotine or saline, depending on group, at a constant rate for 28 days) on resurgence of alcohol seeking in rats. Resurgence is a type of relapse preparation that consists of three phases: Baseline, Alternative Reinforcement, and Resurgence Testing. During Baseline, target responses produced a dipper of alcohol. During Alternative Reinforcement, target responses were extinguished and responses on a chain produced a chocolate pellet. During Resurgence Testing, responses on the chain were also extinguished and a return to responding on the target lever was indicative of resurgence. Multilevel modeling was used to analyze the effect of nicotine on resurgence. Both the nicotine and saline group showed resurgence of alcohol seeking, but there was no difference in the degree of resurgence across groups. Future directions could involve testing alternative drug delivery techniques

    Effects of Acceptance and Commitment Therapy on Impulsive Decision Making

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    This study examined the transdiagnostic effect of acceptance and commitment therapy (ACT) on impulsive decision making in a community sample. Forty adults were randomized to eight individual sessions of ACT or an inactive control. Participants completed pre-, mid-, and post-assessments for psychological symptoms, overall behavior change, valued living, delay discounting, psychological flexibility, and distress tolerance. Data were analyzed with multilevel modeling of growth curves. Significant interaction effects of time and condition were observed for psychological flexibility, distress tolerance, psychological symptoms, and the obstruction subscale of valued living. No significant interaction effect was found for two delay discounting tasks nor the progress subscale of valued living. The ACT condition had a significantly larger reduction of problem behavior at post-assessment. The results support use of ACT as a transdiagnostic treatment for impulsive behaviors. The lack of change in delay discounting contrasts previous research
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